Brigadier General John Bacon McDonald (February 8, 1859 – March 15, 1927) was a senior officer of the United States Army.

John B. McDonald graduated from the United States Military Academy in 1881 and was stationed with the 25th infantry at Fort Randall, but was transferred to the 10th Cavalry in Texas a year later.

He taught Military Science and Tactics from 1888 to 1890 in Auburn, Alabama, before he became quartermaster with the 10th Cavalry in Fort Grant, Arizona 1891.

With the start of the Spanish–American War in 1898, McDonald became lieutenant colonel with the 1st Alabama Volunteer Infantry and was honourably mustered out after the end of the conflict in October 1898.

[1] After the end of World War I, John B. McDonald had several posts, including commander of the Pacific Branch of U. S. Disciplinary Barracks on Alcatraz Island until 1922.